It is sad, that so many are leaving. But is it really their fault. I mean NW is dead lets be honest there, and it has been since last year. They havnt updated anything about BCOF since august 2014, the forum is basically dying if not dead, it doesnt have the spirit like it had 2012-2013. To be honest to hell with this forum,this game and the developers.
There are 4,200 players on warband daily. Thats pretty much been the same for the past 2-3 years. The game isnt dying. http://store.steampowered.com/stats/
Nw is only 3 months older than CSGO lol.
To be fair, that's the number of people playing Warband overall, not just NW. I'd guess that NW and its mods are closer 1,000 or so, which is still decent considering it's a 3 year old DLC. Even so, I definitely don't think we can say that the number of people that stick around is growing. Edit: Bah, Locust beat me to it.
NW is dying, the bigger question is how quickly. A number of the more recognizable names are retiring, and at the moment, I don't see any new names rising to fill their places. But popular names aside, I haven't seen a huge drop-off of average players lately, so I wouldn't say the future isn't as hopeless as some people seem to be saying. It is dark, yes, but not pitch black.